Abstract
In medical research, continuous markers are widely employed in diagnostic tests to distinguish diseased and non-diseased subjects. The accuracy of such diagnostic tests is commonly assessed using the receiver operating characteristic (ROC) curve. To summarize an ROC curve and determine its optimal cut-point, the Youden index is popularly used. In literature, the estimation of the Youden index has been widely studied via various statistical modeling strategies on the conditional density. This paper proposes a new model-free estimation method, which directly estimates the covariate-adjusted cut-point without estimating the conditional density. Consequently, covariate-adjusted Youden index can be estimated based on the estimated cut-point. The proposed method formulates the estimation problem in a large margin classification framework, which allows flexible modeling of the covariate-adjusted Youden index through kernel machines. The advantage of the proposed method is demonstrated in a variety of simulated experiments as well as a real application to Pima Indians diabetes study.
Original language | English (US) |
---|---|
Pages (from-to) | 4963-4974 |
Number of pages | 12 |
Journal | Statistics in Medicine |
Volume | 33 |
Issue number | 28 |
DOIs | |
State | Published - Dec 10 2014 |
Externally published | Yes |
All Science Journal Classification (ASJC) codes
- Epidemiology
- Statistics and Probability
Keywords
- Diagnostic accuracy
- Margin
- Receiver operating characteristic curve
- Reproducing kernel Hilbert space
- Youden index